Concrete mixometer



Feb. 21, 1933. L. A. PERRY CONCRETE MIXOMETER Filed March 12, 1929 \[WENTOR Lem; 19.70113, BY

ATTORNEY Patented Feb. 21', 1933 LEWIS AJJPERRY, or SEATTLE, WASHINGTON CONCRETE MIXOMETER Application 'flled March 12, 1929. Serial No. 346,353.

This invention relates to apparatus for determining the consistency, and other properties of cement concrete mixtures during themaking of the same in a mixing machine.

The quantity of water used in producing a batch of concrete is an extremely important factor as to the quality of the product. According to the accepted doctrine, set forth in what is known as the water-cement ratio strength law, for given materials and conditions of manipulation, the strength of conie is determined solely by the ratio of ve volume of mixing water to the volume of cement so long as the mixture is plastic and workable. Because of the varying amounts of moisture carried by' the aggregatessand, gravel or crushed rockit is impossible without elaborate tests to determine the quantity of water which must be added thereto in the mixer to afford a properly proportioned mixture. Furthermore, as far as I am aware, no attempt has hitherto been made for determining the quality, uniformity and consistency of a concrete mixture by testing the batch itself in the process of making within the mixer prior to its delivery, although follow-up tests with slump tubes are made in the laboratory and in the field from specimens of a concrete mixture.

Such follow-up tests are employed to furnish results which are available after the respective batch, from which a specimen is taken, has been discharged from the mixer and thus render it impossible of use in the direct testing of a batch in the making to correct that particular batch by the addition of Water or solid matter as may be deemed T-requisite. Such follow-up tests, moreover, have been found to be unreliable as to accuracy because of the human equation with the use of-theslump tube. "The object of. the invention is to provide gefiioient means which will automatically test concrete within the mixer to determine the fluidity and uniformity 'of the mixture and cooperating with means located exteriorly of the mixer for indicating to the operator, or to an inspector, the condition of a batch so that it may, if requisite, be corrected in the process of manufacture.

Another object of the invention is the provision of devices which will accomplish the functions above referred to progressively, or otherwise.

The present invention embodies a scale or other weight or pressure indicating means provided exteriorly of a concrete mixer and operatively connected to a governor located within the mixer and adapted to be influ- 60 enced by the impact and weight of portions of the batch being delivered thereupon.

The invention further consists in the novel construction, adaptation and combination of parts hereinafter described and claimed.

In the. accompanying drawing,

Figure 1 is a view partly in side elevation and partly in longitudinal vertical section, on line 11 of Fig. 2, of an embodiment of my invention applied to a concrete mixer; Fig. 2 is a transverse vertical section taken substantially on broken line 2-2 of Fig. 1; and Fig. 3 is a detail horizontal section on. line 33 of Fig. l.

The concrete mixer shown in the drawing to illustrate the application of the invention is of a well known type comprising a cylindrical drum 5 mounted upon rollers 6 for rotation about a horizontal axis.

Said drum is rotated as by means of an endless chain 7 passing about peripherally disposed sprocket teeth 8' provided on the drum and a sprocket wheel 9 provided upon a power driven shaft 10.

The drum 5 is provided centrally of its ends with intake and discharge openings 11 and 12, respectively.

Extending into the intake opening 11 is the spot 13 of a hopper 13 whence measured quantities of Portland cement, sand and gravel, or an equivalent, composing the aggregate, are delivered by gravitation into the drum. Also-extending into said intake opening is a pipe 14 through which water is admitted into the drum from an elevated supply tank 15 which, as shown, is equipped with a tubular sight-glass 16 for disclosing the amount of water within the tank.

17 represents a scale associated with said sight-glass for indicating quantities of water, preferably in gallons, withdrawn from the tank to lower the water-levels thereof to the several graduation marks of the scale. Instead of, or supplementary to, the scale 17 above referred to, there may be provided another'scale (not shown) having thereon graduation marks arranged to indicate volumes of water, denoted in gallons, within the tank to respective marks.

18 represents a service pipe for supplying water into the tank, and 19 is a manually controlled valve for regulating the transfer of selected quantities of. water through the pipe 14 from the tank into the drum 5. Secured to the inner circumferential surface of the drum near its inlet end is a plurality of concrete-mixing blades, such as 20; and in proximity to its discharge end the drum is provided interiorly with a series of buckets 21 as ordinarily used in concrete mixers of the illustrated type. The operation of said blades and buckets are well understood. It may be stated, however, that the blades 20' function to impart movement of the concrete material from the intake end of the drum, to the buckets 21, and the buckets serve to elevate the concrete mixture into their dumping positions above the drums axis of rotation.

22 represents a delivery chute or trough, supported by arms 23 which are connected to an operating shaft 24 whereby the chute is swingable through the discharge opening of the drum from its idle position, in which it is represented by full lines in Fig. 1, into its dotted line position 22 to receive mixedconcrete dumped fromthe buckets 21 successively passing over the receiving end of the chute. 1 t

The plastic-concrete testing apparatus constituting the present invention operates by the action of the concrete itself through lever 30 is connected intermediate its length to the-lower end of a suspension rod 33 dc pending from the arm 34 of a lever which is fulcrumed as at 36 to a rigidsupport; the other arm 35 of said lever carrying a weight 37 which is adjustable tocounter poise the weight of the receiver with no concrete thereon.

38 represents a suitable weighing scale having an.indicator 39 which is operated by the scale mechanism (not shown) actuated by the lever arm 34 when influenced by variations in regard to the mixture load upon or with respect to the/receiver.

40 represents a dash pot containing a fluid in which operates a plunger 41 attached to the lever arm 34 for the purpose of eliminating shocks to the apparatus due to rapid variations in theimpact forces of the successive loads delivered upon said receiver.

The operation of the concrete mixture testing apparatus is as follows: A charge, or batch, of concrete forming material fed into the inlet end of the drum is caused by the rotation of the drum to be mixed through the joint action of the mixing blades 20 and the buckets 21, while the discharge chute 22 occupies the inoperative position in which it is represented by full lines in Fig.

1. In the mixing operation, the plastic concrete is subjected to numerous tumbling actions from elevated positions to which the material is raised by the various blades and buckets in the progressive travel of the mix ture from one end of the drum to the other, as usual. 7

According to the present invention, the portion of the apparatus herein termed the receiver, which is located within the orbit of travel of the buckets has poured or dumped thereupon plastic concrete from the various buckets passing over such receiver in the revoluble travel of the buckets.

Because of the inclined surfaces of the receiver upon which the mixture falls, and to the fluidity of the mixture, the same will flow upon and from the receiverrelatively wet (thin) mixtures flowing more freely than drier mixtures. The weight of the ma:-- terial upon the receiver within the drum acts through the medium of the lever 30, extending from the drum, and suspension rod 33 and lever 3435 outside of the drum to influence the scale 38 whereby the indicator 39 will indicate to the operator the state or condition of the mixture with regard to its consistency and flowability.

It may be said that the continuous weighing of these falling streams of concrete is practically equivalent to an indefinite number of individual weighings, but has the added advantage.ofautomatically giving an average value because several streams are flowing simultaneously into or upon the receiver.

From an inspection of the indicator, it is determinable whether or not a plastic-concrete mixture within the drum conforms to requirements and, if not, what character of ingredients is requisite to cause the mixture to meet such a standard.

When the tested mixture is found satisfactory, the chute 22 is moved into its dotted line 22 position for discharging the batch of concrete from the drum without disturbing the testing apparatus.

My invention is not limited to the details of construction herein illustrated and described, which'may be varied greatly within the scope of the appended claims.

What I claim, is,

1. A plastic-concrete testing apparatus for use in connection with a mixing machine provided with a rotary drum having therein a plurality of buckets, said apparatus comprising a force measuring-and-indicating means disposed exteriorly of said drum," a device provided interiorly of the drum and adapted to be influenced by concrete material falling thereupon from said buckets, and means operatively connecting said device to said measuring-and-indicating means. '1

2. A plastic-concrete testing apparatus as defined in claim 1 characterized by v having in the device a sloping "material-receiving surface. p

3. A plastic-concrete testing apparatus for use in connection with a mixing machine having a rotary drum containing a series 0f-material elevating and dumping buckets, said apparatus comprising a lever extending into the drum, a device supported by said lever interiorly of the drum and within the orbit of travel of the drum buckets to receive plastic concrete material deposited thereupon by the buckets, force measuring means provided exteriorly of the drum, and operative connections between said lever and said force measuring means for actuating the latter to indicate the flowability of the material received upon said device.

4;A plastic-concrete testing apparatus operating in a rotary drum provided with a discharge opening at one end thereof, said drum containing a series of buckets disposed concentrically about its discharge opening. said testing apparatus consisting of a device located within the drum and arranged to receive impulses from concrete material delivered in streams thereon by said buckets in the revoluble travel thereof,

a force measuring means located exteriorly of the drum, and means including a lever extending through the drum discharge opening for operatively connecting said device with said measuring means to indicate the effect of varying plasticities of the concrete delivered upon said device.

5. The combination with a concrete mixing machine having a rotary drum, of a gauge provided exteriorly of the drum, and gauge controlling means operable within the drum for regulating the action of said gauge for indicating the consistency of a concrete mixture.

6. An apparatus for testing the consistency of plastic concrete comprlsing a device operable within the rotary drum of a mixing machine, said device being adapted to be influenced by the impact of falling streams of concrete, and means operatively connected therewith for measuring forces applied by the concrete to said device.

7. The combination with a concrete mixing machine having a rotary drum, of a gauge provided exteriorly of the drum, and gauge-control means providing a restricted orifice operable within the drum for regulating the action of said gauge for indicating the consistency of a concrete mixture.

8. Apparatus for determining the flowability of plastic concrete within a concrete mixer comprising a device provided with a restricted orifice having downwardly converging walls directively disposed thereto upon which plastic concrete delivered thereon is adapted to How.

9. In apparatus as defined in claim 8, wherein said device provides walls sloping downwardly and outwardly from the upper extremity of said converging walls.

10; Apparatus for determining the fiowability of plastic concrete comprising a device adapted for insertion within the path of a stream of concrete and wherein said device is characterized by the provision of downwardly divergent walls forming an apex for impeding the flow of plastic concrete delivered thereto.

11. Apparatus insertable within a concrete mlxer for testing the consistency of the plastic concrete therein comprising a device having an a erture through which the plastic concrete is adapted to flow, and a gauge for indicating the adhesive resistance of the restriction to the flow of the concrete therethrough.

12. In a plastic concrete consistency determining device, means to flow; concrete within a mixer through an orifice formed by the inclined surfaces of a. truncated body, said orifice restricting the flow of the concrete therethrough, and means to measure the adhesive resistance of the concrete to said surfaces.

13. In a device for measuring the consistency of plastic concrete in the process of 5 mixing within a mixer, means causing successive streams of the concrete mixture to pass through an inverted truncated body having inclined inner walls, and means to indicate comparative adhesive resistances of the concrete mixture to the walls during said mixing process.

14. Apparatus for determining the flowability of plastic concrete comprising a device provided with a restricted orifice having downwardly converging Walls directively disposed thereto upon which plastic concrete delivered thereon is adapted to flow and wherein said device provides walls sloping downwardly and outwardly from the upper extremity OI said converging walls.

15. A plastic-concrete testing apparatus, used in connection with a concrete mixing machine, consisting of a device provided with a sloping surface upon which plastic concrete delivered thereupon is adapted to flow, and a gauge operatively connected with said device for indicating the effective wei ht of the concrete supported by said device.

16. An apparatus for testing the consistency ofplastic-concrete comprising a device, introduced within a concrete mixer, upon which the plastic concrete is adapted to be deposited, and a gauge for indicating the effective weight of the concrete supported by said device.

' 17. An automatic plastic-concrete testing apparatus comprising the following co-operative elements, a depressible controller in- 40 sertable within a concrete mixer actuated by streams of concrete in the mixer impacting therewith, and means operatively connected with said controller for indicating the relative deflection of said controller under the influences of said impacting concrete.

18. In an automatic plastic-concrete testing apparatus, the combination with a concrete mixer for delivering concrete in streams, of plasticity indicating means and a controller for said indicating means, said controller being located in the path of'said concrete streams in the mixer, and automatic means o eratively connecting said controller F with said indicator for registering the action of said streams with respect to the controller.

\ Signed at Seattle, Washington, this 2nd dav of March, 1929.

' LEWIS A. PERRY DISCLAEMER 1,898,890.-Lewis A. Perry, Seattle, Wash. CONCRETE MIXOMETER.

Patent dated Feb. 21, 1933. Disclaimer filed Apr. 4, 1945, by the assignee, Pioneer Sand and Gravel Company. Hereby enters this disclaimer to claims 1 to 6 inclusive, 18 in said specification.

[Ofiicz'al (mzette May 8, 1945.]

and claims 15, 16, 17, and 

